204 



GEOLOGY OF THE SECOND DISTRICT. 



The siiifriilar elevation of Mount Marcy distinguishes it from the other objects of calculation 

 in the above table, and entitles it to particular consideration ; more especially so, as some 

 discrepancy exists between the measurements that have hitherto been made. 



Passing over every other personal circumstance connected with my ascent, I cannot but 

 remark, that through the characteristic liberality of the Hon. A. McIntyiie, and the atten- 

 tions of his agent, Mr. Porteus, I was supplied with every tiling needful to my comfort as a 

 guest, and the object of my visit materially promoted. 



The following table embraces all the observations that were made during my stay on the 

 sunnnit. The reductions of the mercurial colunms were made from a table executed by Prof. 

 (1. W. Benedict, with great care and precision, which has regard to tlie effect of temperature 

 uj)on the brass scale, as well as upon the column of mercury. 



The wind, during the whole period, was strong and uniform from the north. Until about 

 eight o'clock, the summit was swept by a cloud of rain and vapor. This gradually disap- 

 peared, producing rapid alternations of storm and sunshine. About ten o'clock, the sky 

 became almost entirely clear. 



It appears from the above notes, that the whole range of the column, embracing the slight 

 but unavoidable errors of observation, is less than six-tenths of a millimetre, or less than three 

 thousandths of an inch. The uniformity of the force and direction of the wind, is a circum- 

 stance favorable to correct results not always found on mountain peaks, which are liable to be 

 swept by variable and conflicting currents. 



From some misunderstanding in regard to lime, and from not attaining the summit as early 

 as I anticipated, only three sets of observations synchronized sufficiently to be employed. 

 The remainder, however, answered the important purpose of verifying those that were 

 taken. 



